I've got a 2004 E320 cdi with the brabus d6 tuning chip, is there a specific procedure to revert the car to stock after unplugging these boxes? every time I unplug the brabus tuning chip and start the car (as stock I'd think) it throws a check engine light on the dash and says fuel Rail pressure too high when using a diagnostic computer.. am I doing something wrong? is there something else I need to do other than just unplug the box?
2004 E320 CDI BRABUS tuning chip CEL
- Thread starter ayvo
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just thought I'd mention upon clearing the code, the first time you start the engine the light stays off, but upon restarting the engine it stays on till the code is reset again, and it's the same if you reset it again, stays off till engine restart.. it does this without the brabus d6 tuning box disconnected but as soon as I connect it its fine, check engine light stays off and it all goes back to normal..
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I think you will need to follow the harness from the Brabus tuning chip to see how it is integrated and reverse that.
A generic tuning box that I have seen plugs inline to the fuel rail pressure sensor so if the box itself was just disconnected then it would leave the circuit incomplete.
A generic tuning box that I have seen plugs inline to the fuel rail pressure sensor so if the box itself was just disconnected then it would leave the circuit incomplete.
Ah, the thing is that it's not one of the brabus tuning boxes that plugs into fuel rail and stuff like that, it's 1 of the older ones that's wired through the ecu with soldering, forgot to mention that..
So the harness will need to be followed and it is likely wired into the ECU harness - this wiring will need to be reversed.
No doubt there will be signal wires that have been cut and joined to wires to the D6 unit - hence you get issues when you simply unplug the unit.
You could always try contacting Brabus and see if they can email you the install guide which should be useful for removal as well.
Brabus - Contact
Yeah I've got the installation guide from brabus, all seems like way too much of a hassle to unwire since its about 6 or 8 different wires soldered to the ecu wires and involves cutting like 1 of the ecu wires too if i remember correctly, was just wondering if it actually was the wiring of the box causing this issue and if there was any way I could revert the car back to stock without having to unwire it all..
Upon checking the installation guide, I noticed that it was the wire from the fuel rail pressure sensor that has to be cut.. so when I unplug the tuning box does it detect an open circuit or something and throw a fuel rail pressure too high code or?
I think that is exactly the case - signal wire becomes open circuit hence the engine light.
I also noticed that without the box the car takes a lot longer to start and the idle is really rough, is this because the values from the fuel rail pressure sensor are unknown or?
Yes there will be no signal from the fuel rail pressure sensor to the ECU.
So if you are intent on removing the unit then it should be easy enough.
The green/violet cable from the rail sensor on pin 59 in Plug M is currently cut and joined to the green/violet and green wire of the D6 unit. Snip these cables with a bit of extra length so you can join and insulate them.
Then simply snip and insulate the remaining 6 out of 8 wires.
so will simply connecting a blanking plug of some sort at the end of the wiring connector that plugs into the brabus box (to close the circuit ig) not help? Will it actually all have to be unwired?
You will need to join the green/violet and green wire of the D6 unit to resume the signal connection when the D6 unit is disconnected.
How you do this is up to you whether using a plug or joining/insulating wires.
yeah, maybe u can have a look and let me know..
this is the one I was having a look at:
Connector blanker
I was actually wondering would it even work and wouldn't it still count it as open circuit with that and still give the check engine light with that because it wouldn't be giving values back to any of it and has no modules or anything inside it or would it be fine?
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That connector looks fine but you would need to join 2 pins inside it to join the green/violet and green wire of the D6 unit.
thanks for all the help, I appriciate it, I'll look into it a little further and decide what to do with it I guess and come back here if I need further help
